package chapter_21_observer.mytest;

/**
 * Created by yao on 2016/11/18.
 */
public class Test {
    public static void main(String[] args) {
        Watcher watcher = new Watcher();
        Watched watched = new Watched(watcher);

        watched.changeAge(2);
        watched.changeAge(2);
        watched.changeAge(3);

    }
}
